Research overview
The text below is the source article’s original abstract under a verified reuse license. cc by
BackgroundNeuronal α-synuclein disease (NSD) is defined by the presence of an in vivo biomarker of neuronal alpha-synuclein (n-asyn) pathology. The NSD integrated staging system (NSD-ISS) for research describes progression across the disease continuum as stages 0 to 6.ObjectiveThe aim was to assess 5-year longitudinal change in NSD-ISS in early disease.MethodsAnalysis included a subset of participants from the Parkinson's Progression Markers Initiative (PPMI) enrolled before 2020 as Parkinson's disease (PD) patients, prodromal PD patients, or healthy controls (HC) who met NSD criteria. Staging was defined based on biomarkers of n-asyn and dopaminergic dysfunction in early stages, clinical features, and severity of functional impairment in stages 3 to 6. Stages were determined annually for 5 years.ResultsOf 576 NSD participants, 494 were enrolled as PD patients, 74 prodromal PD patients, and 8 HCs. At baseline, 24% of participants were stage 2B, 56% Stage 3, 13% stage 4, and less than 5% in other stages. At year 5, the respective percentages for stages 2B to 4 were 11%, 50%, and 34%, indicating progression through NSD stages. Progression was driven by functional impairment in the predominantly motor domain (95%) for stage 2B to 3, increasing degree of nonmotor dysfunction for stages 3 to 4 (46%), and a combination of domains for stages 4 to 5. Initiation of dopaminergic medications led to stage regression in 8% of participants in Stage 3 but 41% in stage 4.ConclusionsOur analysis supports the utility of NSD-ISS in defining the stages of disease progression, at least in the early clinical and prodromal stages (2B, 3, or 4), suggesting the value of NSD-ISS as a potential research tool for drug development. Further research involving preclinical cohorts is a crucial next step. © 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Scientific assessment
Research question
Assess the question within the original study’s scope.
Methods & sample
Check the source article for study design and sample details.
Key findings
An editorially approved findings summary is not yet published for this record.
Limitations
Generalizability, bias and clinical meaning require separate assessment.
Methods, samples and clinical conclusions are not inferred from bibliographic metadata.